DMD in women

The reasoning is sound: A female has two X chromosomes to a male's one, so she has a built-in "backup" if anything should go wrong on either of her two Xs. She can be a "carrier" of an X-linked disease, because she can give a flawed X chromosome to her sons, who, having only one X, will likely develop an X-linked disorder.
DMD is one of many X-linked diseases, such as two kinds of hemophilia...